Process of breaking emulsions



,y 2,700,024' Patented Jan. 18, 1955 Ydce No Drawing. Application January 4, 1951:, Serial N9. 204,471

:6 claims. (cmu-341.)

This invention relates to fsur'face active xcompounds and more kparticularly to lz'zoinpounds verectir'ze -to break certain water-.in-oil emulsions of `the type .met with in crude oil production.

One .of the most Vtroublesome ...problems kvmet with rin crude oil production relates to :the lbreaking :of waterin-oil emulsions yformed in Wells producing both oil and brine. These emulsions are generally foftwo types, the first type being a mechanically cut emulsion, which is usually formed inthe wellby 4faultyrfpumping equipment, the other type .being a gas-.cutrremulsiom the formation 'of which is aided by the` femuls'ifying action `of lcertain .asphaltenes and other chemical emulsiers Eoccurring `naturallyin the crude oil. The emulsion commonlyen- .countered Vis a mixture of both of vthese .types -and its fproperties will vary `fromwell to well, `and teven from vday to day inthe same well, Unless vthese .emulsions can be leffectively and completelyI broken, .the 'oil content is lost.

There are apparently -two rphases ,of van emulsion resolving problem. The -iirst involves a` surface phenomenon in which the oil lilrnsurrounding -the water4 particles of ymicron size .is weakened, fallowing .the-.particles -to .coalesce into Vlarger droplets; this phase will tbe :hereinafter referred to as the emulsion .break-ing step. The Aother involves a splitting of the broken femulsion -into yseparate oil and water phases, and will fbe referred to as the water separation step. p Y

VIt Vhas been found that emulsion breakers described 4in the Yprior art, and available commercially, are gen erally effective in breaking 'a wide variety of emulsions, but may be ineffective in break-ing certain emulsions which may be termed refractory emulsions -in `-that they .are highly resistant -todemulsiiiers commonly used tin the oil iields. The reason for the abnormality of these remulsions is not known, but may be dueto the :fact Ythat the natural emulsiers `occurring in the icrude oil are of za .type not commonly found, and (are resist-ant :to 'the action of chemical fdernulsiiiers effective against emulsi- .iiers more ordinarily encountered. In order to satisfactorily break these emulsions -it is often necessary fto resort to physical ytreatments .such as subjecting the emulsion to the action of -high tension elec-tric felds irl/order to induce coalescence of the water particles. Equipment for so treating the emulsion is-costfly rand presents many problems of upkeep and maintenance `not encountered in the chemical methods of treating emulsions.

rIn this specification, and in the :appended claims, :it 'is -to be understood that by refractory emulsions "We iin- -tend to refer to emulsions which fare highly resistant to the action lof chemical demulsifers 'of the type 'which are eective against the more commonly encountered Water-in-crude-oil emulsions, but which may be easily broken by the action of the new chemical demulsifiers hereinafter disclosed.

We have discovered a series of compounds which have been found to be highly successful in breaking refractory emulsions. Strangely enough, the compounds show little or no breaking action on emulsions which are easily broken by the use of the more commonly used emulsion breakers. They also exhibit poor water separation characteristics, so that in order to obtain a composition which will completely and rapidly resolve a refractory emulsion, it is advisable to blend the new compounds with an agent effective to cause rapid water separation. Typical of such agents are the compounds disclosed in copending applications of William B. Hughes Serial No.

141,597 filed January 31, 1'950 which issued as .-Patent 2,646,405 on July 2'1, -1953 and Serial No. 144,595 led February 16, 1950 on which Patent 2,646,406 issued on July 2l, 1953.

In general our new compounds may be `prepared by reacting two mols of a-primary amine and one mol of an aldehyde to forman intermediate product. The 'reaction product appears to be a mixture of a large number of .unidentified compounds. Attempts have been made yto isolate kpure products by fractionation of the mixture, but no 'appreciable flats could be found in the distillation curve, Various vcuts were 'taken and 'further reacted as described hereinafter in an attempt to 'discover whether `the `higherboilingicuts 'were more effective than the lower boiling 'cuts or vice versa. It was found, howeven'that there was not much, if any variation in 'electivenesa 'and for this'reason we prefer tojut'ilize thecrude reaction mixture, thus avoiding the needless 'expense and trouble involved in effecting the recovery of pure compounds. f

This reaction `commences spontaneously upon mixing the materials, and'will normally go to completion at atmospheric temperatures within a 'few hours. We have foundit desirable, however, to heat the mixture in order to speed up the reaction and to insure that it goes to completion. When heated to about C., the reaction is Aordinarily complete within about one-half hour. The product, an oily liquid, .may then be separated from the water formed in the reaction b y any suitable methods, such as centrifuging or 'decanting The intermediate product iis then neutralized to a pI-I of `about 3.5 bythe reaction product ofa polybasic acid orrits anhydride and castor oil, the acid being used in such proportions that "the reaction product contains free carboxyl radicals. Whenusing dibasic acids, the preferred `proportion is .from about 42, to about 3 mols ofacid'per mol o'f castor oil. The reaction between the `ca'st'or oil and theaeid does inotproceed -spontaneously, and itis geny'erallynec'essary to .heat the reaction massat 1'80" C. or "thereabouts for about two hours in order to complete 'the reaction. The vreaction 'is considered .complete vwhen titration fof the 'product indicates vthat .the 'acid has re- A,act'e'dwith `the castor oil -in 'almost `the *theoretical amount, 'based on the proportion of l'ingredients used.

Any readily 'available Ialdehyde may 'be used, gsuch as formaldehyde, acetaldehyde, ipropionaldehyde, 'buty'ral- 'delig/de, heptafldehyde, or 2higher aldehydes. Formaldehyde is jpreferred, however, because of vits high .reactivity 'and flow cost. Among the ,p'rirnary amines 'useful in `.formulating four -ne'w compounds 'may be included lethyl amine, anyl amine, octyl amine, or `any other functionally 'equivalent amine. As thejpojlybasic acid wejprefer to fuse ph'thalic acid or its anhydride, ibut any 'other equivalent `"polyb'asic acid maybe used.

In -orde'r that those 'skilled in the art may more fully appreciate 'the nature of our new compounds, and th'e method of ,preparing them, the following vexample is given.

Example :Gn'e hundred and seventyffour grams of jmonoa'myl famine, andI 30 grainsofformaldehyde in 'aqueous solution were mixed 'and heated v'at about .100 C. for 'a 'period 'of zone-halffhour to form a hrstntermediate reactionprod- "u'ct. VThis product, which formed an oily layer, was sep- 'a'rajted .from the water layer iby diecantation.

A second intermediate reaction product `was 'then prepared by heating one mol (985 g.) of castor oil with 2.5 mols (370 g.) of phthalic anhydride at C. for a period of about two hours. The irst intermediate was then neutralized with the second intermediate to a pH of 3.5 to form the nal reaction product.

As stated above, the compounds disclosed herein, while effective to break refractory emulsions, in general show poor water separation characteristics. On occasion, however, emulsions will be formed on which the compounds show good water separation, in addition to good breaking action, so that the new compounds alone will resolve the emulsions in a satisfactory manner. In most cases, however, it is preferable, in order to effect rapid water separation from the broken emulsion, to mix the compounds with water separation agents in the proportion of from about 90 to 99 pei' cent of the new compounds to from about l to about per cent of the water separation agent. Nhile any agent which exhibits good water separation characteristics, regardless of any emulsion-breaking effects it exhibits, may be used, Vthe products prepared by reacting at a temperature of about 180 C. and for a time of about two hours one mol of a glyceride of a hydroxy acid having more than 1l carbon atoms with from about 2 to about 3 mols of triethanolamine, neutralized to a methyl orange end-point with a long chain hydroxy acid such as hydroxystearic acid or hydroxy wax acids, as disclosed and described in copending application Serial No. 141,597 filed January 3l, 1950, now Patent 2,646,405 issued on July 21, 1953, and the products prepared by neutralizing a heat polymerized basic hydroxy amine prepared by heating an alkanol amine, in the presence of about l percent sodium hydroxide, to a temperature of from about 225 C. to about 275 C., for a time sutiicient to polymerize the amine to a heavy syrup or solid, to a methyl orange end-point with a long chain hydroxy acid such as ricinoleic acid, hydroxy stearic acid, hydroxy wax acids, or other low-chain hydroxy acids, as disclosed and described in copending application Serial No. '144,595 filed February 16, 1950, now Patent 2,646,406 issued on July 21, 1953, have proven particularly satisfactory.

Our new products also exhibit a synergistic effect when blended with compounds effective to break normal emulsions. Thus, tests of my new materials blended in 50-50 amounts with the amine-carbonyl-propylated naphthalene sulfonate breakers disclosed in our copending application Serial No. 198,915 filed December 2, 1950, now Patent 2,646,404 issued on July 21, 1953, showed that the blend was markedly more eitective than the breaker alone, in some instances, the blend being at least three times as etective as the breaker alone, a

Having now described our invention, what we 'claim as new and useful is: U

l. The process of breaking emulsions which includes mixing with a petroleum Water-in-oil emulsion a quantity of a dual component breaking agent comprising (1) an emulsion resolving agent formed by rst reacting an aldehyde and a primary alkyl amine in the ratio of about one mol of aldehyde to two mols of amine to form a rst intermediate product, then heating together one mol of castor oil and from about two to three mols of a dicarboxylic acid substance at about 180 C. for a period of about two hours to form a second intermediate product, and finally neutralizing the first intermediate product with the second intermediate product to a pH of about 3.5, and (2) a water separation agent effective to cause rapid water separation from a resolved emulsion, and selected from the group consisting of (a) compounds prepared by reacting one mol of a glyceride of a hydroxy acid having more than 11 carbon atoms to the molecule with from about 2 to about 3 mols of triethanolamine at a temperature of about 180 C. for a time of about two hours, and neutralizing the reaction product to a methyl orange end point with a long chain hydroxy acid, and (b) products prepared by neutralizing a heat polymerized basic hydroxy amine prepared by heating an alkanol amine in the presence of about 1 percent of sodium hydroxide to a temperature of about 225 C. for a time suicient to polymerize the amine to a heavy syrup, to. a methyl orange end point with a long chain hydroxy acid, the proportion of water separation agent present in the dual component breaking agent being from about 1 to about 10 percent, the said breaking agent being mixed with the emulsion in an amount small but sufficient to cause substantial resolution of the emulsion, allowing the emulsion to settle into an oil phase and a water phase, and separating the oil from the water.

2. The process according to claim l in which the water separation agent is a compound prepared by reacting one mol of a glyceride vof a hydroxy acid having more than 11 carbon atoms to the molecule with from about 2 to about 3 mols of triethanolamine at a temperature of about C. for a time of about two hours, and neutralizing thereaction product to a methyl orange end point with a long chain hydroxy acid.

3. The process according to claim 1 in which the water separation agent is a product prepared by neutralizing a heat polymerized basic hydroxy amine prepared by heating an alkanol amine, in the presence of about 1 percent sodium hydroxide to a temperature of about 225 C. to about 275 C. for a time sut`n'cient to polymerize the amine to a heavy syrup, to a methyl orange end point with a long chain hydroxy acid.

.4. The process of breaking emulsions which includes mixing with a petroleum water-in-oil emulsion a quantity of a dual component breaking agent comprising (l) the reaction product of one mol of formaldehyde and about two mols of amyl amine, neutralized to a pH of about 3.5 with a product prepared by heating one mol of castor oil and about 2.5 mols of phthalic anhydride at a temperature of about 180 C. for about two hours, and (2) a water separation agent eitective to cause rapid water separation from a resolved emulsion, and selected from the group consisting of (a) compounds prepared by reacting one mol of a glyceride of a hydroxy acid having more than 11 carbon atoms to the molecule with from about 2 to about 3 mols of triethanolamine at a temperature of about 180 C. for a time of about two hours, and neutralizing the reaction product to a methyl orange end point with a long chain hydroxy acid, and (b) products prepared by neutralizing a heat polymerized basic hydroxy amine prepared by heating an alkanol amine in the presence of about l percent of sodium hydroxide to a temperature of about 225 C. to about 275 C. for a time sucient to polymerize the amine to a heavy syrup, to a methyl orange end point with a long chain hydroxy acid, the proportion of water separation agent present in the dual component breaking agent being from about 1 to about 10 percent, the said breaking agent being mixed with the emulsion in an amount small but sucient to cause substantial resolution of the emulsion, allowing the emulsion to settle into a water phase and an oil phase, and separating oil from the water.

5. The process according to claim 4 in which the water 'separation agent is a compound prepared by reacting one mol of a glyceride of a hydroxy acid having more than 11 carbon atoms to the molecule with from about 2 to about 3 mols of triethanolamine at a temperature of about 180 C. for a time of about two hours, and neutralizing the reaction product to a methyl orange end point with a long chain hydroxy acid.

6. The process according to claim 4 in which water separation agent is a product prepared by neutralizing a heat polymerized basic hydroxy amine to a methyl orange end point with a long chain hydroxy acid.

References Cited n the file of this patent UNITED STATES PATENTS 2,303,414 Wayne Dec. 1, 1942 2,440,349 Schae'er Apr. 27, 1948 2,448,626 Schaeffer Sept. 7, 1948 2,491,478 Cook et al. Dec. 20, 1949 

1. THE PROCESS OS BREAKING EMULSIONS WHICH INCLUDES MIXING WITH A PETROLEUM WATER-IN-OIL EMULSION A QUANTITY OF A DUAL COMPONENT BREAKING AGENT COMPRISING (1) AN EMULSION RESOLVING AGENT FROMED BY FIRST REACTING AN ALDEHYDE AND A PRIMARY ALKYL AMINE IN THE RATIO OF ABOUT ONE MOL OF ALDEHYDE TO TWO MOLES OF AMINE TO FORM A FIRST INTERMEDIATE PRODUCT, THEN HEATING TOGETHER ONE MOL OF CASTOR OIL AND FORM ABOUT TWO TO THREE MOLES OF A DICROBOXYLIC ACID SUBSTANCE AT ABOUT 180* C. FOR A PERIOD OF ABOUT TWO HOURS TO FORM A SECOND INTERMEDIATE PRODUCT, AND FINALLY NEUTRALIZING THE FIRST INTERMEDIATE PRODUCT WITH A SECOND INTERMEDIATE PRODUCT TO A PH OF ABOUT 3.5, AND (2) A WATER SEPARATION AGENT EFFECTIVE TO CAUSE RAPID WATER SEPARATION FROM A RESOLVED EMULSION, AND SELECTED FROM THE GROUP CONSISTING OF (A) COMPOUNDS PREPARATED BY REACTING ONE MOL OF A GLYCERIDE OF A HYDROXY ACID HAVING MORE THAN 11 CARBON ATOMS TO THE MOLECULE WITH FROM ABOUT 2 TO ABOUT 3 MOLES OF TRIETHANOLAMINE AT A TEMPERATURE OF ABOUT 180* C. FOR A TIME OF ABOUT TWO HOURS, AND NEUTRALIZING THE REACTION PRODUCT TO A METHYL ORANGE END POINT WITH A LONG CHAIN HYDROXY ACID, AND (B) PRODUCTS PREPARED BY NEUTRALIZING A HEAT POLYMERIZED BASIC HYDROXY AMINE PREPARED BY HEATING AN ALKANOL AMINE IN THE PRESENCE OF ABOUT 1 PERCENT OF SODIUM HYDROXIDE TO A TEMPERATURE OF ABOUT 225* C. FOR A TIME SUFFICIENT TO POLYMERIZE THE AMINE TO A HEAVY SYRUP, TO A METHYL ORANGE END POINT WITH A LONG CHAIN HYDROXY ACID, THE PROPORTION OF WATER SEPARATION AGENT PRESENT IN THE DUAL COMPONENT BREAKING AGENT BEING FROM ABOUT 1 TO ABOUT 10 PERCENT, THE SAID BREAKING AGENT BEING MIXED WITH THE EMULSION IN AN AMOUNT SMALL BUT SUFFICIENT TO CAUSE SUBSTANTIAL RESOLUTION OF THE EMULSION, ALLOWING THE EMULSION TO SETTLE INTO AN OIL PHASE AND A WATER PHASE, AND SEPARATING THE OIL FROM THE WATER. 